Characterization of carbon and iron nanostructures synthesized by the DC arc discharge method: influence of the location in the reactor and of the pressure

¹ Groupe de Physique des Matériaux, UMR CNRS 6634, Institut des Matériaux de Rouen, Université de Rouen, avenue de l'Université, BP 12, 76801 Saint-Étienne du Rouvray, France
² Laboratoire des Solides Irradiés, UMR CNRS 7642, DRECAM-CEA, École Polytechnique, route de Saclay, 91128 Palaiseau, France

Corresponding author: abdeslem.fnidiki@univ-rouen.fr

Received: 1 October 2004
Revised: 17 June 2005
Accepted: 20 July 2005
Published online: 14 December 2005

Abstract

X-ray diffraction, Mössbauer spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques were used to characterize the Fe-C phases in the soots synthesized by the DC arc discharge method. Various equilibrium and non-equilibrium Fe-C compounds were identified, with fractions depending on both the location in the reactor and the helium gas pressure. The soots obtained are composed of the same five phases (C-graphite, α-Fe, γ-Fe, Fe₃C and Fe₅C₂) whatever the helium gas pressure and wherever they are situated in the reactor. However, the location in the reactor has a considerable influence on the size of the particles in the nanostructure. The Fe-C compounds in the Pyrex vessel samples (CL) seem only to be present in the form of nanoparticles embedded in an amorphous gangue, while the water-cooled copper cylinder samples (RS) contain, in addition to these nanoparticles, large composite crystalline particles.